Field of the Invention
The invention relates to a memory and a fabricating method thereof, and particularly relates to a non-volatile memory and a fabricating method thereof.
Description of Related Art
With the evolution of transistor technology, the problem of gate leakage current can be avoided by using a high-k material. Also, processing speed may be faster by using a metal gate. Therefore, a non-volatile memory structure using a high-k/metal gate transistor has been developed.
Take a flash memory as an example. Currently, when a control gate of the flash memory is fabricated using metal gate structures, since the metal gate structures in a flash memory region and a logic device region (e.g., a core device region) are fabricated at the same time, resulting in the problem that a height of the metal gate structure in the flash memory region is insufficient. Thereby, the operating performance of the flash memory is decreased, and even the flash memory may not be normally operated.
Specifically, since the metal gate structures in the flash memory region and the logic device region are fabricated at the same time, and a floating gate and a dummy gate in the flash memory region are stacked disposed in the manufacturing process of the metal gate structure, a height of the dummy gate of the flash memory region is more than a height of the dummy gate of the logic device region. Therefore, when a hard mask layer on the dummy gate of the logic device region is removed by a chemical mechanical polishing method, a portion of the dummy gate in the flash memory region is removed at the same time, resulting in the problem that the height of the metal gate structure formed subsequently in the flash memory region is insufficient.